I bought 2 6 spyder diff kits from bnighs on UE forum. These are the same diffs as in the UE Ultralights (no cases) except the output shafts are stock 7.5. Ben supplied the correct UE diff output shafts, 8mm pinion drive cup and a set of shims as well. I finished shimming the front bulk last week - it took .022 total in shims on the carrier to zero the side to side play and .016 on the pinion (between the pinion and 1st bearing) to set mesh right. If you'll read UE's write up for shimming the Ultralights - its pretty much same kind of thing and all the pics help understand what needs to be done.

You take the freeplay out of the pinion by how you tighten the pinion drive cup. Take the hybrid side that will hold the ring gear face up and place the shimmed pinion with brgs in it. I took a knife blade and placed it between the cup and pinion and applied ever so little pressure to the pinion and then put the drive cup on and tightened the set screw while holdingthis pressure - this removes all the play and will not let the pinion hit the cup. If you just push the drive cup onto the pinion shaft, you'll wind up with play. The pinion should not move in and out when you're finished.

I ran into a prob with the rear hybrid - it would not hold the pinion brgs - it was made with too much clearance. But FLM stood behind it and my replacement should be mailed tomorrow so hopefully, I can finish the rear diff and install these and the cvds this week.

I don't know what the HB diffs need shim wise, but I'd be surprised if they needed no shimming.